CN102261470A

CN102261470A - Sealing system and household appliance with sealing system

Info

Publication number: CN102261470A
Application number: CN2010101909719A
Authority: CN
Inventors: 马敬东; 陶锋; 赵德飞; 丁玉磊; 杨振宇; 黄也贵
Original assignee: BSH Electrical Appliances Jiangsu Co Ltd
Current assignee: BSH Electrical Appliances Jiangsu Co Ltd
Priority date: 2010-05-28
Filing date: 2010-05-28
Publication date: 2011-11-30
Anticipated expiration: 2030-05-28
Also published as: WO2011147900A3; WO2011147900A2; CN102261470B

Abstract

The invention relates to a sealing system and a household appliance with the sealing system. The sealing system comprises first components (16 and 17), a second component (11) and a sealing element (18) for forming seal between the first components (16 and 17) and the second component (11), wherein the first components (16 and 17) are provided with at least one part of groove (30) for accommodating the sealing element (18); and the groove (30) and the sealing element (18) are in a shape which is reduced gradually in the inserting direction (C) of the sealing element (18), and the head part (60) of the sealing element (18) is smaller than an opening (61) of the groove (30).

Description

Sealing system and household appliance having such a sealing system

[ technical field ]

The invention relates to a sealing system and to a domestic appliance, such as a refrigerator, having such a sealing system.

[ background art ]

Sealing systems are widely used in household appliances, such as refrigeration appliances. For example, in the case of a refrigeration appliance having an evacuable storage compartment (also referred to as a "low-pressure chamber" or a "vacuum chamber"), the storage compartment must have high sealability in order to prevent external air from entering the storage compartment after the storage compartment is evacuated.

In a refrigeration device having an evacuable storage chamber (low pressure chamber) disclosed in chinese patent application No. CN101358797A, a low pressure chamber main body having a food access port is configured to include: a box-shaped resin outer contour forming the taking and placing opening, a glass plate made of tempered glass, and a metal plate-shaped component extending along a plurality of inner wall surfaces of the resin outer contour. The glass plate is hermetically placed in the upper opening of the outer contour made of resin by an annular gasket, wherein the annular gasket has a structure including an upper portion, a side portion and a lower portion so as to cover the upper surface, the side surface and the lower surface of the edge portion of the glass plate, respectively, and the glass plate is fitted into a groove formed by the upper portion, the side portion and the lower portion and is held by the elastic force of the gasket. An opening having a step is formed in the upper part of the resin outer contour, an annular gasket is placed on the step, the gasket is deformed by the weight of the glass plate and the pressure difference between the inside and the outside of the low pressure chamber, and the sealing property between the glass plate and the opening is ensured. This sealing system requires the position of the glass plate and the opening, which does not work well in case the opening is arranged at the side, or bottom, of the low pressure chamber.

US 4,923,260 discloses a sealing system for use on refrigerator shelves. The sealing system is used between the frame of the shelf and the glass plate, and comprises a frame with a U-shaped receiving groove, and the edge of the glass plate is inserted into the receiving groove of the frame after being inserted into the sealing element with the U-shaped groove. Such a sealing system may be suitable for sealing between two components having different relative positions. For such a sealing system, the sealing element needs to have a certain elasticity and form an interference fit with the receiving groove, which makes it difficult to insert the sealing element into the receiving groove in a flat manner.

[ summary of the invention ]

The object of the present invention is to provide an improved sealing system and a household appliance having such a sealing system.

Accordingly, one aspect of the present invention pertains to a sealing system comprising: a first member; a second component; and a sealing element to form a seal between the first component and the second component, the first component having a recess to receive at least a portion of the sealing element; characterized in that the groove and the sealing element each have a shape which tapers in the insertion direction of the sealing element, and the head of the sealing element is smaller than the opening of the groove.

Thereby, it becomes easier to align and insert the sealing member into the groove, thereby facilitating the assembly of the sealing member. In addition, the large opening and small bottom shape of the injection molded recess is also particularly advantageous for the mold drawing step during its molding. By suitable arrangement of the sealing element and the recess, it is expected that a more reliable sealing effect will be formed between the sealing element and the recess as the sealing element is driven deeper.

Other features which are considered as characteristic for the invention, individually or in combination with other features, are set forth in the following appended claims.

According to a preferred embodiment of the present invention, the groove has at least one inclined surface extending in the insertion direction and a bottom surface, and the sealing member includes a side sealing portion to be brought into close contact with the inclined surface and the head portion to be brought into close contact with the bottom surface. The formation of a plurality of sealing areas between the sealing element and the groove makes the sealing effect between the two more reliable.

According to a preferred embodiment of the present invention, the outer surface of the side sealing part and the slope have substantially the same inclination angle.

According to a preferred embodiment of the invention, the angle of the inclined surface with respect to the central axis plane of the groove is not less than 4 degrees, for example 5 to 6 degrees.

According to a preferred embodiment of the invention, the groove has a pair of oppositely disposed side surfaces to form a pair of opposite inclined surfaces, the bottom surface connects the pair of inclined surfaces, and the pair of inclined surfaces and the bottom surface form a succession of three sealing surfaces with the sealing element.

According to a preferred embodiment of the invention, the sealing element has a receiving groove for receiving an edge portion of the second component, which receiving groove is surrounded by the three successive sealing surfaces.

According to a preferred embodiment of the invention, the sealing element has a substantially U-shaped cross-section.

Another aspect of the invention relates to a household appliance comprising a sealing system as described in any of the above.

According to a preferred embodiment of the invention, the domestic appliance comprises a low-voltage storage unit with an evacuable storage compartment, the first part and the second part being parts of the low-voltage storage unit which are constructed separately and fixed together.

According to a preferred embodiment of the invention, the first part is made of plastic and the second part is made of metal and forms a main portion of the low-pressure reservoir.

According to a preferred embodiment of the invention, the second part is a box-like structure having at least one port, the first part is connected to a rim portion of the port, and the sealing element is provided along the entire rim portion of the port.

According to a preferred embodiment of the present invention, a fixing unit for fixing the first member and the second member is included, the fixing unit causing the head portion to be kept pressed and deformed in the insertion direction.

The construction of the present invention and other objects and advantages thereof will be more apparent from the following description of the preferred embodiments taken in conjunction with the accompanying drawings.

[ description of the drawings ]

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. Wherein,

fig. 1 is a schematic perspective view of a refrigeration appliance according to a preferred embodiment of the present invention, wherein the door of the refrigeration appliance is not shown.

Fig. 2 is a schematic assembled perspective view of a low pressure storage unit according to a preferred embodiment of the present invention.

Fig. 3 is a schematic perspective view of a low pressure storage unit according to a preferred embodiment of the present invention when it is opened.

Fig. 4 is a schematic perspective exploded view of a main body of a low pressure storage unit according to a preferred embodiment of the present invention.

Fig. 5 is a partial perspective view of a rear cover according to a preferred embodiment of the present invention.

Fig. 6 shows a partly sectional schematic view of a state of a sealing element before insertion into a groove according to a preferred embodiment of the invention.

Fig. 7 is a schematic partial sectional view taken along a-a direction in fig. 2.

Fig. 8 is an enlarged view of a portion B in fig. 7.

[ detailed description of the invention ]

Referring to fig. 1, a refrigerator 1 includes a heat-insulating box 2, and the box 2 includes a casing 2a, an inner container 2b, and a heat-insulating layer (not shown) therebetween. The cabinet 2 defines a plurality of insulated storage compartments 3, 4, 5 for storing items such as food. In the present embodiment, these storage compartments are respectively a cold storage compartment 3 located at the upper part, a freezer compartment 5 located at the bottom part and a fresh food compartment 4 located between the two, the temperature of which is kept slightly above zero degrees centigrade. The storage compartments 3, 4, 5 can be closed by respective doors (not shown).

It should be understood that the present invention should not be limited to a specific distribution of the storage compartments of the refrigeration appliance, but the present invention can also be applied to other forms of refrigeration appliances, such as a refrigerator having a refrigerating compartment and a freezing compartment in an up/down/up distribution, a side-by-side refrigerator, a refrigerator having a drawer type door and/or a french side-by-side door, and the like.

The refrigeration appliance 1 has an evaporative refrigeration system forming a closed loop. The refrigeration system includes at least a compressor (not shown), a condenser (not shown), a throttle device (not shown), and an evaporator (not shown). Since such a refrigeration system is well known in the art, further description thereof will be omitted.

The refrigerator 1 is provided with a low-pressure storage unit 7 having an evacuable storage compartment 32 and with a suction device (not shown) for drawing gas from the storage compartment 32. The evacuation means may comprise a vacuum pump and a line (not shown) connected between the vacuum pump and the low pressure storage unit 7.

In this embodiment, the low-pressure storage unit 7 is disposed within the fresh food compartment 4. The low-pressure storage unit 7 is located at the bottom of the fresh food compartment 4 and is supported on the bottom wall of the fresh food compartment 4. In this embodiment, a fresh-keeping container 6 with high humidity and suitable for keeping food such as vegetables is disposed above the low-pressure storage unit 7. It should be understood that in other embodiments, the low-pressure storage unit 7 may be disposed in other storage compartments, such as the refrigerating compartment 3 or a temperature-changing compartment whose temperature range is switchable between a refrigerating temperature zone and a freezing temperature zone.

Fig. 2 is a schematic assembled perspective view of the low pressure storage unit 7 according to a preferred embodiment of the present invention. Fig. 3 is a schematic perspective view of the low pressure storage unit 7 when it is opened according to a preferred embodiment of the present invention. Referring to fig. 2 and 3, in the present embodiment, the low pressure storage unit 7 is substantially a flat rectangular parallelepiped, and includes a main body 8 having one end opened and a drawer-type container 9 movably received in the main body 8.

The main body 8 defines a flat housing space having a front end opening. The drawer-type container 9 has a door 10 formed on the front wall thereof for closing the front end opening of the main body 8, and a tray-like container body 12 attached to the rear side of the door 10 for holding the articles. The main body 8 is received and fixed in the housing 2, and the main body 8 is preferably detachably fixed in the fresh food compartment 4. The user obtains the articles located in the low pressure storage unit 7 by pulling the drawer type container 9.

The width of the main body 8 and the width of the door 10 are respectively slightly smaller than the width of the fresh-keeping compartment 4, so that the main body 8 and the door 10 can be inserted into the fresh-keeping compartment 4 or pulled out from the fresh-keeping compartment 4, and therefore, gaps are formed between the two sides of the low-pressure storage unit 7 and the inner container 2b of the fresh-keeping compartment 4. In order to block such a gap, the low pressure storage unit 7 may include a gap blocking member 50, which is deformable, provided at a front end of the main body 8.

The housing 40 of the low pressure storage unit 7 is composed of the main body 8 and the door 10 of the drawer type container 9. The housing 40 defines an evacuable storage compartment 32 with the tray-like container body 12 located within the storage compartment 32. In the present embodiment, the storage chamber 32 is substantially formed by the housing space of the main body 8.

When the storage chamber 32 is closed by the door 10 and the air extractor is activated, air located within the storage chamber 32 is extracted and the storage chamber 32 is at a low pressure. According to a preferred embodiment of the present invention, at the end of the evacuation process, the pressure within the storage chamber 32 is between one standard atmosphere and an absolute vacuum (e.g., less than 690 millibars absolute). The skilled person also colloquially refers to the "vacuum chamber" as the pressure in the storage chamber 32 is lower than the standard atmospheric pressure. In the present embodiment, the storage chamber 32 has a volume of about 20L.

The front end of the body 8 and/or the door 10 may be provided with sealing elements (not shown) to enable an airtight engagement between the body 8 and the door 10 when the drawer container 9 is in the fully closed position, preventing gas from entering the storage compartment 32 from the engagement between the body 8 and the door 10.

A retractable rail unit 14 is provided between the drawer-type container 9 and the main body 8 so that the drawer-type container 9 can be smoothly pulled out of or pushed into the main body 8.

The door 10 is provided with an inflation passage (not shown) for fluidly communicating the inside and outside of the storage chamber 32 and an inflation valve (not shown) for opening or closing the inflation passage. When the air charging valve opens the air charging passage, external air can be introduced into the storage chamber 32 through the air charging passage to release the low pressure state of the storage chamber 32.

The door 10 is provided at a front end thereof with a handle 13, and the user can operate the drawer type container 9 through the handle 13. In a preferred embodiment, the air-filling valve is operatively associated with the handle 13 in such a manner that when the handle 13 is operated, the air-filling valve is opened to place the reservoir chamber 32 in fluid communication with the exterior, so that air can enter the reservoir chamber 32 to release the low pressure state of the reservoir chamber 32. In other embodiments, the inflation valve may be provided separately from the handle 13, such as by providing a button on the door 10 that is depressed to open the inflation valve, after which the user may open the door 10 by manipulating the handle 13.

The door 10 constituting the front wall of the storage chamber 32 is made of plastic which is easy to mold due to a relatively complicated structure of an air-filling valve, a handle 13, and the like. In the present embodiment, the door 10 is made of ABS resin (acrylonitrile-butadiene-styrene copolymer).

The inner surface of the door 10 is exposed to the storage chamber 32, and the outer surface constitutes a part of the outer contour of the low pressure storage unit 7 to form a part of the wall of the storage chamber 32. The door 10 is required to withstand a pressure difference between the inside and the outside when the storage compartment 32 is in a low pressure state, and the tray-shaped container body 12 is not required to withstand the pressure because it is located inside the storage compartment 32, and therefore, the door 10 has a larger wall thickness than the tray-shaped container body 12. In this embodiment, the thickness of the door 10 is 6 mm, and the thickness of the tray-shaped container body 12 may be about 1 to 2 mm.

Fig. 4 is a schematic perspective exploded view of the body 8 according to a preferred embodiment of the present invention. Referring to fig. 4 in conjunction with fig. 2 and 3, the main body 8 includes a box-shaped box body 11 having front and rear ends opened, a rear cover 16 fixed to the rear end of the box body 11 to close a rear port 26 of the box body 11, and a front connection unit 17 fixed to the edge of a front port 25 of the box body 11.

Sealing elements 18 are provided between the box body 11 and the rear cover 16 and between the box body 11 and the front connection unit 17, respectively, so that an airtight connection is formed between the box body 11 and the rear cover 16 and the front connection unit 17, respectively.

In the present embodiment, the box body 11 includes a top wall 21, a bottom wall 23, and left and right side walls 22 connected between the top wall 21 and the bottom wall 23, which are made of a metal having a relatively high material strength. The cartridge body 11 constitutes a main part of the housing 40. In the present embodiment, the inner sides of the metal top wall 21, the bottom wall 23, and the left and right side walls 22 are exposed to the storage chamber 32, the outer surfaces thereof constitute a part of the outer contour of the low-pressure tank unit 7, and constitute most of the upper wall, the lower wall, and the both side walls of the storage chamber 32, and the inner side of the front connecting unit 17 is also exposed to the storage chamber 32, and thus constitutes a minute part of the upper boundary, the lower boundary, and the both side boundaries of the storage chamber 32. When the storage chamber 32 is in a low pressure state, the box body 11, the front connection unit 17, and the rear cover 16 are subjected to a pressure caused by the pressure inside the storage chamber 32 being lower than that outside. It should be understood that in other embodiments it is also possible that the upper, lower and both side walls of the storage compartment 32 are formed entirely from the metal body 11.

The top wall 21, bottom wall 23, left and right side walls 22 may be made of steel plate and have a wall thickness of no greater than 4 mm, and most preferably, these walls 21-23 have a wall thickness of 2 mm to 2.5 mm.

The top wall 21, bottom wall 23 and left and right side walls 22 of the box body 11 are preferably of one-piece construction, thereby reducing or even eliminating the connecting seams between these walls. In the present embodiment, the top wall 21, the bottom wall 23, and the left and right side walls 22 are formed by welding a steel plate (cold-rolled plate) bent into a rectangular shape. As shown in fig. 3 and 4, the weld 33 is located in the middle portion of the right side wall 22, which is advantageous, on the one hand, to reduce the possibility of air leakage of the weld 33 under pressure, since the side wall 22 is subjected to a lower pressure than the top wall 21 and the bottom wall 23, and on the other hand, to facilitate the setting of the jig during the welding step; in addition, this also contributes to a more aesthetic refrigeration appliance 1, since the weld is provided on a side wall that is less noticeable to the user.

It should be understood that in other embodiments, it is also possible for the top wall 21, the bottom wall 23, and the left and right side walls 22 of the box body 11 to be formed by joining (e.g., welding) a plurality of metal plates.

Alternatively, the body may be made of other metallic materials, such as aluminum. In the case of a box body made of aluminum, the box body is preferably obtained in its entirety by an extrusion process. Since the modulus of elasticity of aluminium is lower than that of steel, the wall thickness of the box body made of aluminium is preferably greater than 2 mm, for example 4 mm.

In the present embodiment, the top wall 21 and the bottom wall 23 have a symmetrical structure, and constitute the wall of the box body 11 having the largest area. When the low pressure storage unit 7 is in a low pressure state, the top wall 21 and the bottom wall 23 are subjected to a greater pressure than the other walls of the low pressure storage unit 7. To increase the moment of inertia of the top and

bottom walls

21, 23, the top and

bottom walls

21, 23 are each stamped with a plurality of outwardly projecting raised areas 34.

In order to fix the front connection unit 17 and the rear cover 6 to the box body 11 without perforating the top wall 21, the left and right side walls 22 and the bottom wall 23, according to a preferred embodiment of the present invention, as shown in fig. 3, 4 and 7, mounting pieces 27 are provided on the outer sides of the top wall 21, the bottom wall 23 and the left and right side walls 22, respectively, in the front and rear end regions of the box body 11. The mounting plate 27 may be made of metal, such as steel plate.

Each mounting tab 27 includes a connecting foot 27a that is horizontally secured to the corresponding wall 21-23. In the present embodiment, the mounting piece 27 is fixed to the box body 11 by welding the connecting leg portions 27a to the respective walls 21 to 23. In other embodiments, the mounting tab 27 may be secured to the box body 11 in other ways, such as by being adhesively attached to the box body.

The mounting piece 27 includes an extension portion 27b bent from the connecting leg portion 27a and extending outward. In this embodiment, the extension 27b is generally perpendicular to the respective walls 21-23. The extension portion 27b is plate-shaped, having flat front and rear surfaces. The extending portions 27b at the front and rear ends of the box body 11 are spaced from the front and rear end faces of the box body 11, respectively.

In the present embodiment, the extension portion 27b and the connecting leg portion 27a together constitute the mounting piece 27 having an L-shaped cross section. However, in other embodiments, the extension portions 27b may be integrally formed on the respective walls 21-23 to extend directly outwardly from the respective walls 21-23 of the container body 11.

Each of the extension portions 27b is provided with a plurality of first holes 31a penetrating front and rear surfaces thereof. Preferably, the first holes 31a of each of the extension portions 27b are spaced apart from each other by a predetermined distance and arranged in a row. The first holes 31a at the front and rear ends of the cartridge body 11 form a rectangular frame having a size larger than the front/

rear ports

25, 26, respectively, and the cartridge body 11 is surrounded by the corresponding rectangular frame. The first hole 31a at the rear end of the box body 11 is internally provided with threads, and the first hole 31a at the front end of the box body 11 is not provided with threads.

The structures of the rear cover 16 and the front connection unit 17 according to a preferred embodiment of the present invention are described in detail below.

As shown in fig. 4 and 7, the rear cover 16 is connected to the rear port 26 of the box body 11, and constitutes a rear wall of the housing 40 to define a rear boundary of the storage chamber 32. The rear cover 16 has a plate shape corresponding to the square of the rear port 26, and has a size larger than that of the rear port 26 and extends beyond the rear port 26.

The rear cover 16 is provided with a suction passage (not shown) penetrating the rear cover 16 and a suction valve unit 36 for selectively closing or opening the suction passage. In this embodiment, the suction valve unit 36 extends above the top wall 21, with a connection port 39 located above the top wall 21. The low pressure storage unit 7 is connected to a pipe fixed to the tank 2 through a connection port 39 so that the low pressure storage unit 7 can be in fluid communication with the suction device.

The rear cover 16 includes a main body wall portion 20 constituting a substantial portion thereof and a rear connecting portion 19 provided around the periphery of the main body wall portion 20 to connect the rear cover 16 to the edge of the rear port 26. The rear connection portion 19 is connected to the entire edge of the rear port 26.

In the present embodiment, the rear connecting portion 19 and the main body wall portion 20 are integrally injection-molded from plastic having a lower modulus of elasticity than metal. Preferably, the rear cover 16 is made of Polycarbonate (PC) which is a material having a large strength. The thickness of the main body wall portion 20 made of PC is about 6 mm. To enhance the strength of the main wall portion 20, the rear surface of the main wall portion 20 may be further provided with a plurality of ribs 35.

It should be understood that in other embodiments, the rear attachment portion 19 may also be provided separately from the main body wall portion 20 and then secured in an airtight connection to form the rear cover 16, which is particularly advantageous in cases where the rear attachment portion 19 and the main body wall portion 20 are made of different materials.

The front connection unit 17 is connected to the entire edge of the front port 25, and has a square frame-shaped structure forming a closed loop. The front attachment unit 17 has an abutment surface 37 for abutment with the door 10, the abutment surface 37 being flat in this embodiment and lying in the same longitudinal plane. When the door 10 is closed, the seal on the door 10 is compressed between the abutment surface 37 and the door 10 to effect a seal.

In order to connect the front connection unit 17 and the rear cover 16 to the cartridge body 11 in a gas-tight manner, the front connection unit 17 and the rear cover 16 are each provided with an annular recess 30 for receiving the annular sealing element 18 on the side facing the cartridge body 11. The front and rear ends of the top wall 21, the side wall 22 and the bottom wall 23 of the box body 11 are inserted into the corresponding grooves 30, respectively, and the sealing member 18 is located between the grooves 30 and the box body 11.

Outside the recess 30, the front connection unit 17 and the rear cover 16 are respectively provided with a plurality of second holes 31 b. These second holes 31b are respectively located on portions of the front connection unit 17 and the rear connection unit 19 beyond the outer surfaces of the top wall 21, the side walls 22, and the bottom wall 23 so as to be located outside the storage chamber 32. The second holes 31b on the front connection unit 17 and the rear cover 16 form a rectangular frame having a size larger than the front/

rear ports

25, 26, respectively.

In the present embodiment, the second hole 31b on the front connection unit 17 extends forward from the rear side of the front connection unit 17 without penetrating the front connection unit 17, and is a blind hole having a thread formed therein to fix the screw 29. The second hole 31b on the rear cover 16 extends forward from the rear side of the rear connection portion 19 and penetrates the rear connection portion 19 as a through hole for the corresponding screw 29.

The front connection unit 17 is integrally injection-molded from plastic. In the present embodiment, since the screw holes for fixing the screws 29 are provided on the front connection unit 17, the front connection unit 17 is injection-molded by mixing PC resin having a relatively high strength and ABS resin having a relatively high toughness to balance the strength and toughness thereof.

The fixing manner between the front connection frame 17, the rear cover 16 and the box body 11 is described in detail below.

The front attachment unit 17 and the rear cover 16 are fixed to the front and rear ends of the box body 11 by a plurality of fixing units, respectively.

In the present embodiment, each of the fixing units includes a screw 29, a first hole 31a provided on the mounting piece 27 of the cartridge body 11, and a second hole 31b provided on the front attachment unit 17/the rear cover 16, and the front attachment unit 17/the rear cover 16 are securely fixed to the cartridge body 11 by inserting the screw 29 into the first hole 31a and the second hole 32b and forming a screw-fastening with the first hole 31a or the second hole 32b having a screw therein, respectively. The fixing unit provides a preload between the front connection unit 17 and the cartridge body 11 and between the rear cover 16 and the cartridge body 11 in such a manner that the screw 29 is fixed, so that the sealing member 18 between the front connection unit 17/the rear cover 16 and the cartridge body 11 can be pressed, which can enhance the sealing effect between the front connection unit 17/the rear cover 16 and the cartridge body 11.

In other embodiments, other fixing elements capable of providing pre-tightening force can be used for the fixing unit. For example, the screws may be replaced with bar-shaped fixing members integrally injection-molded on the front connection unit 17 and the rear cover 16, and in this case, the second holes 31b provided on the connection frame 17 and the rear cover 16 may be omitted.

In the present embodiment, since the first and

second holes

31a and 31b are located entirely outside the reservoir chamber 32, the inside of the reservoir chamber 32 is not in fluid communication with the outside due to the arrangement of the first and

second holes

31a and 31 b. In addition, since the first hole 31a and the second hole 31b are located outside the annular seal member 18, the first hole 31a and the second hole 31b are virtually isolated from the storage chamber 32 and do not communicate. In this way, the possibility of outside air entering the storage chamber 32 through the first and

second holes

31a, 31b is eliminated, that is, these first and

second holes

31a, 31b do not adversely affect the airtightness of the storage chamber 32, thereby contributing to the improvement in airtightness of the low-pressure storage unit 7.

In the embodiment of the present invention in which the housing 40 of the low pressure storage unit 7 is made of a metal having a large material strength, in the embodiment of the present invention, the housing 40 of the low pressure storage unit 7 is made of a first member (such as the box body 11) made of a metal having a large material strength and a plurality of second members (the front connection unit 17, the rear cover 16 and the door 10) made of a plastic having a relatively small material strength and being easily molded, thus, on the one hand, the first component can obtain larger strength to bear the external pressure with smaller wall thickness, thereby reducing the deformation generated when the storage chamber 32 is in a low pressure state and improving the airtightness of the storage chamber 32, this advantage is particularly pronounced in the case where the walls (top and bottom walls 21 and 23) of the storage compartment 32 having the largest area are made mainly or entirely of metal, this advantage is particularly pronounced when the main body portion of the housing 40 is made of metal; on the other hand, since the housing further includes the second members (e.g., the rear cover 16, the door 10, the front connection unit 17) made of plastic, which are subjected to pressure when the storage chamber 32 is in a low pressure state, relatively complicated, high-precision, high-sealing-requirement structures (e.g., an inflation valve, an air-extraction valve unit, etc., which are required to have high airtightness) may be provided on these second members to improve airtightness of the low-pressure storage unit. Further, since the first member made of metal can have a small wall thickness and is excellent in heat transfer performance, heat can be transferred well between the inside and the outside of the storage chamber even if the second member has a large wall thickness. In addition, when the second member constitutes only a small portion of the housing, in particular it no longer has a box-shaped structure, its forming process is relatively easy, and at the same time, they do not have a significant influence on the heat transfer inside and outside the low pressure storage unit 7, since it is only a small portion of the low pressure storage unit 7.

A preferred embodiment of the sealing system between the body 11 and the front and

rear connection units

17, 16 is described in detail below.

In the present embodiment, the sealing members 18 for the front connection unit 17 and the rear cover 16 have substantially the same structure, and the structure in which the front connection unit 17 and the rear cover 16 are butted is also substantially the same, and therefore, only the sealing system between the rear cover 16 and the main body unit 11 will be described below as an example.

Referring to fig. 4 to 8, the annular groove 30 is formed along the periphery of the rear cover 16, and is open to a side facing the main body unit 11 to form an opening 61. The groove 30 is located within the rectangular frame formed by the second hole 31 b.

The sealing element 18 is elastic and preferably made of silicone rubber. The sealing element 18 has a closed-loop frame shape corresponding to the shape and size of the rear port 25. The sealing member 18 has a receiving groove 65 for receiving an edge portion of the rear port 25. Preferably, after the sealing member 18 is fitted over the entire edge portion of the rear port 25, the sealing member 18 is inserted into the groove 30 together with the edge portion of the rear port 26.

The groove 30 has a shape that tapers in the insertion direction C of the sealing element 18. Thus, in the same cross-section, the opening 61 of the groove 30 has the largest dimension compared to the rest of it.

The recess 30 includes a pair of oppositely disposed inclined surfaces 62 extending in the insertion direction C and a bottom surface 63 connected between the inclined surfaces 62. The angle between the inclined surface 62 and the central axial plane D of the recess 30 is preferably not less than 4 degrees, for example, 5 to 6 degrees. The ramp 62 is formed by the side inner surfaces of the groove 30.

The sealing element 18 has a substantially U-shaped cross-section. The sealing member 18 includes a pair of side sealing portions 64 to be in close contact with the inclined surfaces 62 and a head portion 60 connected between the pair of side sealing portions 64. The housing groove 65 is surrounded by the side wall seal 64 and the head 60.

The outer contour of the sealing element 18, which is formed by the side seal 64 and the outer surface of the head 60, is also tapered in the insertion direction C of the sealing element, so that the head 60 has the smallest dimension in comparison with the rest of the sealing element 18 in the same cross section.

The outer surface of the side seal portion 64 and the corresponding inclined surface 62 have substantially the same inclination angle. Preferably, the shape and size of the outer contour of the sealing element 18 in the free state substantially corresponds to the groove 30. When the sealing member 18 is inserted into the groove 30, the sealing member 18 can be smoothly aligned and inserted into the groove 30 since the head 60 of the sealing member 18 is smaller than the opening 61 of the groove 30. As the sealing member 18 is progressively deeper, the side seal 64 of the sealing member 18 progressively contacts the ramp 62. While the head portion 60 of the seal member 18 is brought into close contact with the bottom surface 63 and pressed to be shortened to produce a seal surface therebetween, the side seal portion 64 having an inclined outer surface is also pressed by the inclined surface 62 to be deformed and brought into close contact with the inclined surface 62 to form a seal surface. After that, the rear cover 16 and the body unit 11 are fixed together by a fixing unit including a screw 29 so that the head 60 is kept pressed to produce a shortening deformation in the insertion direction C.

Since the sealing member 18 and the groove 30 respectively have a shape that is tapered in the insertion direction C of the sealing member 18, it becomes easier to align the sealing member 18 and insert it into the groove 30; in addition, even if the side seal portion 64 of the sealing member 18 is not pressed by the inclined surface 62 of the groove 30 before the head portion 60 is pressed to shorten or the pressing force to which is applied is small (which is advantageous for the insertion of the sealing member 18), the side seal portion 64 moves further forward to be pressed by a smaller portion of the groove 30 as the head portion 60 is pressed to shorten, thereby enabling a good seal to be formed between the side seal portion 64 and the inclined surface 62.

In addition, the three successive sealing surfaces formed between the sealing element 18 and the recess 30 make the sealing between them particularly reliable, while the edge portion of the rear port 26 can be clamped very tightly in the receiving groove 65 to form the three successive sealing surfaces.

It should be understood that the sealing system described above should not be limited to use between the body unit 11 and the front attachment unit 17/rear cover 16, but may be used between any two components that are separately constructed and secured together. It is obvious that it can also be applied to household appliances other than refrigeration appliances (e.g. water heaters, washing machines, cooking utensils).

Claims

1. A sealing system, comprising:

a first part (16, 17);

a second member (11); and

a sealing element (18) to form a seal between the first part (16, 17) and the second part (11), the first part (16, 17) having a recess (30) to receive at least a portion of the sealing element (18);

characterized in that the groove (30) and the sealing element (18) each have a shape that tapers in the insertion direction (C) of the sealing element (18), and in that the head (60) of the sealing element (18) is smaller than the opening (61) of the groove (30).

2. Sealing system according to claim 1, wherein the groove (30) has at least one bevel (62) extending in the insertion direction (C) and a bottom surface (63), the sealing element (18) comprising a side sealing portion (64) for tight contact with the bevel (62) and the head portion (60) for tight contact with the bottom surface (63).

3. The sealing system of claim 2, wherein the outer surface of the side seal (64) and the chamfer (62) have substantially the same angle of inclination.

4. A sealing system according to claim 2 or 3, wherein the angle of the chamfer (62) with respect to the neutral axis plane (Z) of the groove (30) is not less than 4 degrees, such as 5-6 degrees.

5. A sealing system according to claim 2, 3 or 4, wherein the groove (30) has a pair of oppositely disposed side surfaces to form a pair of opposite inclined surfaces (62), the bottom surface (63) connecting the pair of inclined surfaces (62), the pair of inclined surfaces (62) and the bottom surface (63) forming a succession of three sealing surfaces with the sealing element (18).

6. A sealing system according to claim 5, wherein the sealing element (18) has a receiving groove (65) for receiving an edge portion of the second component (11), the receiving groove (65) being surrounded by the three successive sealing surfaces.

7. Sealing system according to any one of the preceding claims, characterized in that the sealing element (18) has a substantially U-shaped cross-section.

8. A domestic appliance comprising a sealing system as claimed in any preceding claim.

9. The household appliance according to claim 8, comprising a low-voltage storage unit (7) with an evacuable storage compartment, the first part (16, 17) and the second part (11) being parts of the low-voltage storage unit (7) which are separately constructed and fixed together.

10. Household appliance according to claim 8 or 9, wherein said first part (16, 17) is made of plastic and said second part (11) is made of metal and forms a main portion of said low-voltage storage unit (7).

11. An electric household appliance as claimed in claim 8, 9 or 10, characterized in that the second component (11) is a box-shaped structure having at least one port (25, 26), the first component (16, 17) being connected to a rim portion of the port (25, 26), the sealing element (18) being provided along the entire rim portion of the port (25, 26).

12. Household appliance according to claim 8, 9, 10 or 11, characterized in that it comprises a fixing unit to fix said first part (16, 17) and said second part (11), said fixing unit causing said head (60) to remain pressed and deformed in said insertion direction.